Materials Data on Fe2CoO4 by Materials Project

Abstract

CoFe2O4 is Spinel-like structured and crystallizes in the trigonal P3_121 space group. The structure is three-dimensional. there are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to four O2- atoms to form FeO4 tetrahedra that share corners with six equivalent FeO6 octahedra and corners with six CoO6 octahedra. The corner-sharing octahedra tilt angles range from 55–59°. There is two shorter (1.92 Å) and two longer (1.95 Å) Fe–O bond length. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six equivalent FeO4 tetrahedra, edges with two equivalent FeO6 octahedra, and edges with four CoO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.04–2.06 Å. There are two inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with six equivalent FeO4 tetrahedra, edges with two equivalent CoO6 octahedra, and edges with four equivalent FeO6 octahedra. There are a spread of Co–O bond distances ranging from 2.09–2.14 Å. In the second Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with six equivalent FeO4 tetrahedra, edges with two equivalent CoO6 octahedra, and edges with four equivalent FeO6 octahedra. There are a spread of Co–O bond distances ranging from 2.10–2.13 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Fe3+ and two Co2+ atoms. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Fe3+ and two Co2+ atoms. In the third O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Fe3+ and one Co2+ atom. In the fourth O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Fe3+ and one Co2+ atom.